In high-frequency wireless communication systems, high antenna gain and directivity, and broad coverage are typically design trade-offs. Wireless communication systems having broad coverage often sacrifice beam directivity and efficiency. Broader coverage allows an antenna system to potentially serve more users and more devices. Likewise, wireless communication systems having good directivity and a high gain antenna system having long link distances, do so at the expense of coverage area.
Directivity is generally a characteristic of a main lobe or main beam generated by the antenna or antenna array. Antenna arrays are typically designed to avoid grating lobes that draw power from the main beam, although many arrays still generate grating lobes when steering the main beam. Directivity characterizes the ability of the antenna to focus power in a particular direction, an increase in which narrows the coverage of the antenna.